An electric control system for the HVAC computing room generally aims to monitor and manage all equipments and operation states of the computing room in a centralized way. Those equipments to be monitored and managed constitute subsystems of the computing room, including a main machine operation system, a cooling tower operation system, a thermal water boiler system, a constant pressure water supply system, a water filtering and treatment system, motorized valve system, and a deoxidizing device system. In prior arts, the main machine of the air-conditioner is controlled by a separated control box, another separated control box is further provided for electrically controlling the chilled water pump, the cooling water pump and the thermal water pump, a further separated control box electrically controls the cooling tower, and the constant pressure water supply device, the water treatment device, and the motorized valve are respectively provided with an additional control box for electric control. All those control boxes are positioned close to related devices, or in a unified way according to customer demands. That may cause a large space occupation, and the electronic control boxes only realize the basic function of device control, but can achieve neither the function of operation state checking and monitor-displaying on each of the equipments, nor the function of control linkage or state checking. In addition, as the box is designed according to the power of the devices or according to different configurations of different manufacture, the control boxes have varying specifications, thus affecting the whole appearance of the computing room. Generally, the line arrangement of this HVAC computing room is realized by manual wiring in a field-bus way, which leads to a high technical requirement on field workers. This kind of field arrangement not only causes materials waste, but also prolongs the arrangement period of the computing room.